The XMM-Newton Large-Scale Structure (XMM-LSS) X-Ray Source Catalog contains the source list for the first 5.5 surveyed square degrees of the XMM-LSS, with a total of 3385 point-like or extended sources above a detection likelihood of 15 in either 0.5 - 2 keV or 2 - 10 keV bands. The agreement with deep log N- log S is excellent. The main parameters considered are position, count rate, source extent with associated likelihood values. A set of additional quantities such as astrometric corrections and fluxes are further calculated while errors on the position and count rate are deduced from simulations. This table contains the main parameters, while further parameters and data products (X-ray images and optical thumbnails) are available at the Milan XMM-LSS database site: <a href="http://cosmos.iasf-milano.inaf.it/~lssadmin/Website/LSS/Query">http://cosmos.iasf-milano.inaf.it/~lssadmin/Website/LSS/Query</a>; This table was created by the HEASARC in February 2008 based on the CDS Catalog J/MNRAS/382/279 file xlss.dat. This is a service provided by NASA HEASARC .